Slips, trips, and falls (STFs) represent one of the leading causes of occupational injuries and fatalities. In particular, many prior reports have linked STFs with the onset of low-back disorders, which, depending on the severity of the incident, can leave the worker physically limited both in the workplace and at home. In contrast, the incidence and outcomes of loads acting on the low back due to a slip and trip that does not lead to a fall (i.e., slip/trip without fall: STWF) remain only marginally investigated to date. To address this research deficit, this quantitative study was designed to explore selected physiological outcomes of STWFs. In terms of methodology, participants completed several walking trials during which two unexpected perturbations involving a slip and trip were introduced (a harness prevented a fall). A biomechanical model developed using the AnyBody modeling software yielded trunk kinematics and muscle geometry. These outputs - along with the electromyography of fourteen lumbar flexor and extensor muscles - were employed as input data for our 3D, dynamic, EMG-based lumbar spine model. Results of (a) lumbar kinematics (range of the motion of the trunk relative to the pelvis), (b) lumbar muscle activity, (c) lumbosacral reaction forces, and (d) moments all indicated more than a two-fold increase during the slip and trip trials compared to normal walking. Specifically, reported values for the slip trial were (a) 45°, (b) 0.694, (c) 2939 N, and (d) 52 Nm; Reported values for the trip trial were (a) 42°, (b) 0.691, (c) 2898 N, and (d) 50 Nm; and the analogous figures for normal walking were (a) 19°,(b) 0.195, (c) 1174 N, and (d) 16 Nm. Findings from this study can be used to develop interventions to avoid such incidents; for example, to determine specific training parameters (e.g., frequency, duration, and intensity) to optimize a developed intervention’s effectiveness. Such approaches may lead to the control of specific mechanisms involved with lowback disorders consequent to a slip or trip, and potentially reduce the risk for slip- and trip-related injuries.

Library of Congress Subject Headings

Falls (Accidents); Back--Diseases--Mathematical models; Back--Diseases--Prevention

Publication Date


Document Type


Student Type


Degree Name

Industrial and Systems Engineering (MS)

Department, Program, or Center

Industrial and Systems Engineering (KGCOE)


Ehsan Rashedi

Advisor/Committee Member

Matthew Marshall


RIT – Main Campus

Plan Codes